This invention relates to a manipulator for presenting a strip for welding to a welding machine and to a method of presenting a strip for welding to a welding machine.
A previous apparatus for presenting a strip for welding into a band saw to a welding machine has used a pre-programmed robot to effect the manipulation. Disadvantages arise with this arrangement because of the high initial costs of purchasing a robot system and the difficulty encountered by robots when handling blades of a very long length.
Another known manipulation technique is by means of manual labour to clamp the adjacent ends of the strip in a welding machine. This has obvious disadvantages in that a number of clamping operations may be required to achieve an accurate positioning of the two ends and also the high costs involved with manual labour.
It is an object of the present invention to address the above mentioned disadvantages.
According to a first aspect of the present invention a manipulator for presenting a strip for welding to a welding machine comprising strip adjustment means and end clamp means for clamping end sections of the strip, which adjustment means are operable to adjust the position of end sections of the strip in the end clamp means, and which end clamp means are operable to clamp end sections of the strip and to manipulate the strip from a substantially elongate configuration to a loop configuration for welding.
The strip may be an unwelded band saw blade.
The strip adjustment means may be mounted for movement transverse to the length of a strip.
The strip adjustment means may be operable to move between a first position in which at least one end section of the strip is spaced from the end clamp means and a second position in which said at least one end section of the strip is substantially adjacent to the end clamp means.
The strip adjustment means may be operable to pull the strip through the end clamp means, said pulling may be effected until at least one end detector detects an end of the strip. The manipulator may include one end detector for each end of the strip. The strip adjustment means may include a clamp, which may be arranged to hold the strip in position during said pulling.
The strip adjustment means may be mounted for substantially vertical movement. The strip adjustment means may, in use, cause a loop of the strip to be pulled upwardly when moving to said second position. Said loop may be supported by rollers of the strip adjustment means, which rollers may have relative locations which provide a smooth curve over which the loop may rest. The rollers may permit movement of the loop relative thereto.
The end clamp means may comprise two or more clamp sections. Where two clamp sections are provided one may be located to one side of the strip adjustment means and the second to the opposite side of the strip adjustment means. Each clamp section may comprise two clamps.
The end clamp means may be operable to move between a strip receiving configuration and a loop delivery configuration.
The strip receiving configuration may comprise at least one opening of the end clamp means being aligned along a longitudinal axis of the strip, when the strip is in the elongate configuration.
The loop delivery configuration may comprise at least one opening of the end clamp means being aligned along a longitudinal axis of the end sections of the strip when the strip is in the loop configuration. The longitudinal axis of the end sections when in the loop configuration is preferably at a different, preferably higher, level than the longitudinal axis of the strip when in the elongate configuration.
The end clamp means may be mounted to pivot between said strip receiving and said loop delivery configurations.
The end clamp means may comprise at least one clamp mounted on an arm, one end of the arm may be pivotally mounted. The arm may comprise two sections formed at an angle to each other. Said angle may permit said at least one clamp to move between different levels when the arm is pivoted, which pivoting may be through substantially 180xc2x0. The different levels may be those of the strip end sections when in the strip receiving configuration and in the loop delivery configuration.
The end clamp means may be operable to adjust the relative positions of the strip ends, said adjustment may be in addition to the adjustment by the strip adjustment means.
The end clamp means may be operable to clamp the strip with variable degrees of force.
The manipulator may be movable between a strip receiving position and a transfer position for transferring a strip for welding to a welder.
According to a second aspect of the present invention, a method of manipulating a strip for presentation to a welding machine comprising receiving a strip in a manipulator in a substantially elongate configuration in end clamp means, adjusting the position of at least one end section of the strip in the end clamp means with strip adjustment means and manipulating the strip from said substantially elongate configuration to a loop configuration for welding with said end clamp means.
The strip may be clamped by a first clamp of the end clamp means when it reaches a chosen position relative to the first clamp, said position may be dictated by an end stop.
The adjustment of the said at least one end section may be an adjustment in a second clamp of the clamp means, which adjustment may be effected while said first clamp is activated.
The strip may be cut from a greater length of material after initial adjustment of the strip.
The strip adjustment means may adjust the position of the strip by pulling a section of the strip through the end clamp means. The adjustment may be transverse to the longitudinal axis of the strip.
The adjustment may be made until an end detector detects that at least one end section of the strip is close to the end clamp means.
Preferably the method includes the end clamp means comprising clamps located at opposite sides of the strip adjustment means. Preferably, there is at least one clamp for each end section of the strip.
The manipulation of the strip preferably comprises pivoting the clamps between a first position in which the end sections of the strip point substantially away from each other to a second position in which the end sections point towards each other and are in close proximity to each other.
The pivoting between first and second positions preferably comprises a turn through substantially a half circle.
The manipulation step is preferably followed by the strip being presented to a welder, preferably by movement of the manipulator towards the welder.
According to a third aspect of the present invention a welding station for receiving a loop for welding from a manipulator according to the first aspect comprising at least one welding machine mounted on a turntable and a loop support section.
The loop support section may be arranged to support a loop during a welding operation.
The turntable may be arranged to move between a first, loop receiving position and a second, loop discharge position. The welding machine may be arranged to weld said loop whilst moving between said first and second positions.
A discharge section may be arranged to remove a welded loop from the loop support section by means of relative movement between the discharge section and the loop support section. Preferably, supports of the discharge section are operable to lift a loop from the loop support section.
The welding section may comprise at least two welding machines, which may be located at opposite sides of the turntable.
Where at least two welding machines are provided, the welding station may be arranged to receive a manipulated loop in a first of the welding machines while a second of the welding machine has another loop removed therefrom by the discharge section.
According to a fourth aspect of the present invention a method of welding a loop for welding received from a manipulator according to the first aspect comprises supporting the loop on a loop support section and welding the loop with a welding machine while the welding machine is moved on a turntable between a loop receiving position and a loop discharge position.
According to a fifth aspect of the present invention a loop manipulation and welding machine comprises a loop manipulator according to any aspect of the first aspect of the present invention and a welding station according to any aspect of the third aspect.
According to a sixth aspect of the present invention, a method of manipulating a strip for welding and welding said strip comprises the methods of any aspects of the second and fourth aspects of the present invention combined.
Any of the above aspects can be combined with any of the features disclosed herein, in any combination.